I. Field
The present disclosure relates generally to electronics, and more specifically to a receiver for a wireless communication system.
II. Background
A wireless device in a wireless full-duplex communication system can simultaneously transmit and receive data for two-way communication. In the transmit path, a transmitter within the wireless device may modulate a local oscillator (LO) signal with data to obtain a modulated signal and may amplify this modulated signal to obtain a transmit signal having the proper signal level. The transmit signal may be routed through a duplexer and transmitted via an antenna to a base station. In the receive path, a receiver within the wireless device may obtain a received signal via the antenna and the duplexer. The receiver may amplify, filter, and downconvert the received signal to obtain baseband signals, which may be further processed to recover data transmitted by the base station.
For a full-duplex wireless device, the circuitry within the receiver may observe interference from the transmitter. For example, a portion of the transmit signal may leak from the duplexer to the receiver, and the leaked signal (which is commonly referred to as a transmit (TX) leakage signal) may cause interference to a desired signal within the received signal. Since the transmit signal and the desired signal typically reside in two different frequency bands, the TX leakage signal can normally be filtered and typically does not pose a problem in itself. However, the TX leakage signal may interact with a jammer to generate cross modulation distortion components on both sides of the jammer. A jammer is a large amplitude undesired signal that is close in frequency to a desired signal. Some distortion components from the interaction between the TX leakage signal and the jammer may fall within the signal band of the desired signal and would not be filtered out. These distortion components would act as additional noise that may degrade performance. Furthermore, the TX leakage signal may go through a downconverter in the receiver and cause second-order distortion, which is proportional to the square of the TX leakage signal power.
There is therefore a need in the art for techniques to mitigate the deleterious effects of a TX leakage signal in a wireless device.